| Al-Ula International Airport | ULH | Al-Ula | SA |
| Ambrolauri Airport | — | Ambrolauri | GE |
| Baikal International Airport | UUD | Ulan Ude | RU |
| Batken Airport | — | Batken | KG |
| Bilorai Airport | UGU | Bilogai | ID |
| Bugulma Airport | UUA | Bugulma | RU |
| Bulgan Airport | UGA | Bulgan | MN |
| Buol - Pogogul Airport | UOL | Buol | ID |
| Commander in Chief of FALINTIL, Kay Rala Xanana Gusmão, International Airport | UAI | Suai | TL |
| Concord-Padgett Regional Airport | USA | Concord | US |
| Domingo Faustino Sarmiento Airport | UAQ | San Juan | AR |
| Donoi Airport | ULZ | Uliastai | MN |
| El Caraño Airport | UIB | Quibdó | CO |
| Francisco B. Reyes (Busuanga) Airport | USU | Coron | PH |
| Gulu Airport | ULU | Gulu | UG |
| Gurayat Domestic Airport | URY | Gurayat | SA |
| Hewanorra International Airport | UVF | Vieux Fort | LC |
| Indian Mountain LRRS Airport | UTO | Utopia Creek | US |
| Jaluit Airport | UIT | Jabor Jaluit Atoll | MH |
| José Cleto Airport | UVI | União da Vitória | BR |
| Joya Andina International Airport | UYU | Quijarro | BO |
| K. D. Matanzima Airport | UTT | Mthatha | ZA |
| Kazarman Airport | — | Kazarman | KG |
| Khuzhir Airport | — | Khuzhir, Olkhon Island | RU |
| Kiunga Airport | UNG | Kiunga | PG |
| Kobe Airport | UKB | Kobe | JP |
| Kumejima Airport | UEO | Kumejima | JP |
| Kuressaare Airport | URE | Kuressaare | EE |
| Kursk East Airport | URS | Kursk | RU |
| Lensk Airport | ULK | Lensk | RU |
| Lugovoy Airport | — | Lugovoy | RU |
| Mabuiag Island Airport | UBB | Mabuiag Island | AU |
| Maharana Pratap Airport | UDR | Udaipur | IN |
| Manshuk Mametova International Airport | URA | Uralsk | KZ |
| Mário de Almeida Franco Airport | UBA | Uberaba | BR |
| Mariscal Sucre International Airport | UIO | Quito | EC |
| Mestia Queen Tamar Airport | — | Mestia | GE |
| Natakhtari Airfield | — | Natakhtari | GE |
| Northeast Florida Regional Airport | UST | St Augustine | US |
| Nyala Airport | UYL | Nyala | SD |
| Ölgii Mongolei International Airport | ULG | Ölgii | MN |
| Omolon Airport | — | Omolon | RU |
| Omsukchan Airport | — | Omsukchan | RU |
| Orlando de Carvalho Airport | UMU | Umuarama | BR |
| Oskemen International Airport | UKK | Ust-Kamenogorsk (Oskemen) | KZ |
| Ouvéa Airport | UVE | Ouvéa | NC |
| Phu Cat Airport | UIH | Quy Nohn | VN |
| Quelimane Airport | UEL | Quelimane | MZ |
| Quetta International Airport | UET | Quetta | PK |
| Quilpie Airport | ULP | — | AU |
| Quincy Regional Airport Baldwin Field | UIN | Quincy | US |
| Ranong Airport | UNN | Ranong | TH |
| Razzakov Airport | — | Isfana | KG |
| Rubem Berta Airport | URG | Uruguaiana | BR |
| Samui International Airport | USM | Na Thon (Ko Samui Island) | TH |
| Sultan Hasanuddin International Airport | UPG | Makassar | ID |
| Surat Thani Airport | URT | Surat Thani | TH |
| Susuman Airport | — | Susman | RU |
| Ten. Cel. Aviador César Bombonato Airport | UDI | Uberlândia | BR |
| Tolka Airport | — | Tolka | RU |
| U-Tapao–Rayong–Pattaya International Airport | UTP | Rayong | TH |
| Ua Huka Airport | UAH | Ua Huka | PF |
| Ua Pou Airport | UAP | Ua Pou | PF |
| Ubon Ratchathani Airport | UBP | Ubon Ratchathani | TH |
| Udon Thani International Airport | UTH | Udon Thani | TH |
| Ufa International Airport | UFA | Ufa | RU |
| Ujae Atoll Airport | UJE | Ujae Atoll | MH |
| Ukhta Airport | UCT | Ukhta | RU |
| Ulaanbaatar Chinggis Khaan International Airport | UBN | Ulaanbaatar (Sergelen) | MN |
| Ulaangom Airport | ULO | Ulaangom | MN |
| Ulanqab Jining Airport | UCB | Ulanqab | CN |
| Ulsan Airport | USN | Ulsan | KR |
| Ulyanovsk Baratayevka Airport | ULV | Ulyanovsk | RU |
| Ulyanovsk Vostochny Airport | ULY | Cherdakly | RU |
| Umeå Airport | UME | Umeå | SE |
| Una-Comandatuba Airport | UNA | Una | BR |
| Unalakleet Airport | UNK | Unalakleet | US |
| Union Island International Airport | UNI | Union Island | VC |
| Upington Airport | UTN | Upington | ZA |
| Uray Airport | URJ | Uray | RU |
| Urgench International Airport | UGC | Urgench | UZ |
| Uruapan - Licenciado y General Ignacio Lopez Rayon International Airport | UPN | Uruapan | MX |
| Ürümqi Tianshan International Airport | URC | Ürümqi | CN |
| Urzhar Airport | UZR | Urzhar | KZ |
| Usharal Airport | USJ | Usharal | KZ |
| Ushuaia - Malvinas Argentinas International Airport | USH | Ushuaia | AR |
| Usinsk Airport | USK | Usinsk | RU |
| Ust-Kut Airport | UKX | Ust-Kut | RU |
| Ust-Kuyga Airport | UKG | Ust-Kuyga | RU |
| Ust-Maya Airport | UMS | Ust-Maya | RU |
| Ust-Nera Airport | USR | Ust-Nera | RU |
| Ust'-Kamchatsk Airport | — | Ust'-Kamchatsk (Krutoberegovo) | RU |
| Utila Airport | UII | Utila Island | HN |
| Utirik Airport | UTK | Utirik Island | MH |
| Utkela Airport | UKE | Bhawanipatna | IN |
| Uzhhorod International Airport | UDJ | Uzhhorod | UA |
| Yamaguchi Ube Airport | UBJ | Ube | JP |
| Yulin Yuyang Airport | UYN | Yulin | CN |
| Yuzhno-Sakhalinsk International Airport | UUS | Yuzhno-Sakhalinsk | RU |